Heterogeneity of eukaryotic replicons, replicon clusters, and replication foci.

摘要: According to the current paradigm, replication foci are discrete sites in interphase nucleus where assemblies of DNA enzymes simultaneously elongate forks 10–100 adjacent replicons (each ∼100 kbp). Here we review new results and provide alternative interpretations for old show that paradigm is need further development. In particular, many larger than previously thought – so large their complete takes much longer (several hours) measured average time at individual (45–60 min). addition this heterogeneity replicon size, it now apparent there also a corresponding size intensity foci. An important property all they stable structures persist, with constant dimensions, during cell cycle stages including mitosis, therefore likely represent fundamental unit chromatin organization. With mind, present modified model which composed clusters small as proposed, but number per focus extremely heterogeneous, significant proportion single replicons. We speculate very may extend over two or more organization be regulating such proceeds through S-phase.